I went to racking the slide rather than hitting the release after a few sessions of shooting in the cold with and without gloves. The slide release just wasn't there for my partially numb thumbs or gloved thumbs. I can easily manipulate a slide with partially numb hands, so that's what I practice. (Note: the mag release is significantly easier to manipulate, even using partially numb or gloved hands. Just mash it until it's even with the frame!)